Wikipedia: Stephen Hawking
02.10.2006 - 2:33 pm

Professor Stephen William Hawking, D.Phil., CH, CBE, FRS, (born January 8, 1942) is one of the world's leading theoretical physicists. Hawking is the Lucasian Professor of mathematics at the University of Cambridge (a post once held by Sir Isaac Newton), and a fellow of Gonville and Caius College, Cambridge. Despite being severly handicapped by amyotrophic lateral sclerosis, a severe motor neurone disease, he has had a hugely successful career and has achieved status as a worldwide celebrity.

Biography
Stephen was born in Oxford, England, on January 8, 1942, exactly 300 years after the death of Galileo Galilei. His parents were Frank Hawking, a researcher on tropical medicine, and Isobel Hawking, a Communist sympathizer and friend of Robert Graves. Stephen's mother received a star atlas that day, which the friend who gave it to her would later say that, taken along with his birthdate, guaranteed that he would become a scientist and study the cosmos. Of his family, Stephen would be closest to his mother. He had two younger sisters and an adoptive brother. One of his sisters became a doctor and one, Philippa Hawking, studied with Joseph Needham.

Hawking showed great talent in mathematics and physics at an early age. He was educated at St Albans School, in Hertfordshire, and at University College, Oxford, where he obtained a first-class honours degree in Natural Science. During this time, he had been particularly interested in thermodynamics, relativity theory, and quantum mechanics. He later remarked that much of his time at Oxford was spent explaining how he had got the answers to his assignments. He has also claimed that he only spent about 1000 hours studying while there. He moved to Cambridge University to complete his Ph.D. in cosmology at Trinity Hall; he was subsequently elected to a fellowship at Gonville & Caius College, which he continues to hold. While at Cambridge in 1965, he married Jane Wilde, the daughter of George and Beryl Wilde, whom he had met at a New Year's party in St. Albans in 1963. (Ferguson, 1991: 42, 47). He divorced Jane in 1990 (they had 3 children � named Tim, Lucy and Robert � and now have a grandchild), and married his second wife, Elaine Mason, in 1995. Jane Hawking chronicled their marriage and its dissolution in her 1999 memoir, Music to Move the Stars. Recently Jane and Lucy Hawking, a novelist, have raised concerns about violent tensions between Stephen and Elaine, resulting in a police investigation but no charges.

Hawking was elected as one of the youngest fellows of the Royal Society in 1974, was created a Commander of the Order of the British Empire in 1982, and became a Companion of Honour in 1989. He is a respected physicist, with many works recognised by both the International Association of Natural Physics and the American Physics-Astronomy Guild of Amherst. Stephen also enjoys inspiring young people into science, and emphasizing that just because a person is physically disabled, he is not necessarily mentally disabled.

Research fields
Hawking's principal fields of research are theoretical cosmology, quantum gravity, and string theory. In 1971, in collaboration with Sir Roger Penrose, he provided mathematical support for the Big Bang theory of the origin of the universe; if the general theory of relativity was correct, the universe must have a singularity, or starting point, in space-time. Hawking also suggested that, after the Big Bang, primordial or mini black holes were formed. He showed that, neglecting quantum mechanical effects, the surface area of a black hole can increase but never decrease, derived a limit to the radiation emitted when black holes collide, and that a single black hole cannot break apart into two separate black holes. In 1974, he calculated that black holes thermally create and emit subatomic particles until they exhaust their energy and explode. Known as Hawking radiation, this theory was first to describe a mathematical link among gravity, quantum mechanics, and thermodynamics. In 1981, Hawking proposed that, although the universe had no boundary, it was finite in space-time; 1983 saw his mathematical proof of this.

Illness
Despite being severely disabled by amyotrophic lateral sclerosis, a motor neuron disease, Hawking is highly active in physics, writing, and public life. The disease makes it necessary for Hawking to carry out in his head the long and complex calculations that his work requires.

When he was young, he was athletic and enjoyed riding horses and playing with the other children. At Oxford, he joined the rowing team, which he stated helped relieve his immense boredom at the school. This athleticism, however, was soon to change. Symptoms of the disorder first appeared while he was enrolled at Cambridge. Diagnosis came when Hawking was 21, shortly before his first marriage, and doctors said he would not survive more than two or three years. He battled the odds and has survived much longer, although he has become increasingly disabled by the gradual progress of the disease. He has used an electronic voice synthesiser to communicate since a tracheostomy in 1985 that followed severe pneumonia. He gradually lost the use of his arms, legs, and voice, and is now almost completely paralysed. The computer system attached to his wheelchair is operated by Hawking manually through a blink recogniser, implanted in his glasses. By blinking and scrunching his cheeks up, he is able to talk; compose speeches, research papers, and books; browse the World Wide Web; write e-mail; and perform most other computer tasks. The system also uses radio transmission to provide control over doors, lights, and lifts at his home and office. Hawking has jokingly complained that his computer-synthesized voice speaks with an American accent, though he is quick to add that technicians are working on a unit that will speak with a British accent.

When he was first living with just his wife, and was confined to a wheelchair and unable to dress himself, they would hire physics students to help him, which allowed Hawking cheap care. Eventually Hawking needed a real caregiver. He also needed a wheelchair that would help him not be distracted by his disability. Hawking�s current wheelchair can go up to 30 miles an hour, though when he �walks� with people, he likes to go six or seven miles per hour.

There is every chance that he would never have made the discoveries he has were it not for the support of his family. Despite his disease, he describes himself as "lucky" � not just because its slow progress allowed him time to make influential discoveries but because it afforded him time to have, in his own words, "a very attractive family"[1]. When Jane was asked why she decided to marry a man with a 3-year life expectancy, she responded: "These were the days of atomic gloom and doom, so we all had rather a short life expectancy."

Distinction
Hawking took up Einstein's mantle and solved many of the paradoxes of relativity by theorising the existance of objects with very high mass and zero space with gravity so crushing that they absorb all light and are hence invisible. The theory has since been refined to fall in line with quantum mechanics and with general developments in physics.

In addition to academic work, Hawking believed that the average person should have access to these concepts and wrote a series of popular science books. His first book, A Brief History of Time, was published on April 1, 1988 and became a documentary in 1991 starring Hawking, his family and friends who have known him as well as some leading physicists, [2] It surprisingly became a best-seller, and was followed by The Universe in a Nutshell (2001). Both books have remained highly popular all over the world. A collection of essays, Black Holes and Baby Universes (1993) was also popular. He has now written a new book, A Briefer History of Time (2005) that aims to update his earlier works and make them more accessible to a wider audience.

As well as intelligence, the man is known for wit. Hawking is famous for his oft-made statement, "When I hear of Schr�dinger's cat, I reach for my gun." This was a deliberately ironic paraphrase of the phrase "When I hear the word 'culture', I reach for my Browning", from a play by German playwright and Nazi Poet Laureate, Hanns Johst. His witty way with words has both entertained the non-specialist public and helped them to understand complex questions. Asked recently (October 2005) to explain his assertion on the British daytime chat show Richard and Judy that the question, "What came before the big bang?" was meaningless, he compared it to asking, "What lies north of the north pole?"

As well as his serious academic side and humour, Hawking is an active supporter of various causes. He appeared on a political broadcast for the United Kingdom's Labour Party, and actively supports the children's charity SOS Children's Villages. He also reportedly agreed to take part in a protest against the war in Iraq.

Losing an old bet
Hawking was in the news in July 2004 for presenting a new theory about black holes which goes against his own long-held belief about their behaviour, thus losing a bet he made with Kip Thorne and John Preskill of Caltech. Classically, it can be shown that information crossing the event horizon of a black hole is lost to our universe, and that as a consequence all black holes are identical, beyond their mass, electrical charge and angular velocity (the "no hair theorem"). The problem with this theorem is that it implies the black hole will emit the same radiation regardless of what goes into the black hole, and as a consequence that if a pure quantum state is thrown into a black hole, an "ordinary" mixed state will be returned. This runs counter to the rules of quantum mechanics and is known as the black hole information paradox. (For further detail see Thorne Hawking Preskill bet)

One other bet - about the existence of black holes - was described by Stephen as an "insurance policy" of sorts. To quote from his book, A Brief History of Time, "This was a form of insurance policy for me. I have done a lot of work on black holes, and it would all be wasted if it turned out that black holes do not exist. But in that case, I would have the consolation of winning my bet, which would win me four years of the magazine Private Eye. If black holes do exist, Kip (Kip Thorne) will get one year of Penthouse. When we made the bet in 1975, we were 80 percent certain that Cygnus was a black hole. By now, I would say that we are about 95 percent certain, but the bet has yet to be settled." (1988)

Hawking had earlier speculated that the singularity at the centre of a black hole could form a bridge to a "baby universe" into which the lost information could pass; such theories have been very popular in science fiction. But according to Hawking's new idea, presented at the 17th International Conference on General Relativity and Gravitation, on 21 July 2004 in Dublin, Ireland, black holes eventually transmit, in a garbled form, information about all matter they swallow:

The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.
�GR Conference website summary of Hawking's talk.

Having concluded that information is conserved, Hawking conceded his bet in Preskill's favour, awarding him Total Baseball, The Ultimate Baseball Encyclopedia, an encyclopedia from which information is easily retrieved. However, Thorne remains unconvinced of Hawking's proof and declined to contribute to the award.

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